He uses a technique called time blocking,in which he dedicates several hours to a single task, to help strengthen focus and eliminate distraction. The co-founder and chairman of Austin, Texas-based Keller Williams Realty blocks out the first four hours of every day and says time blocking helped him turn a local office into the largest real estate franchise in the United States.

"It may sound extreme, but it's honestly one of the simplest and most effective tactics for anyone to live by."

Keller shares these four time-blocking tips that entrepreneurs can use to get more done:

1. Identify your top priority. Keller looks at his goals for the year and asks himself, "What's the one thing which, when tackled, will make everything else I have to do easier or unnecessary?" He then designs the first four hours of his workdays around doing that one thing.

For example, when Keller was working on his book, he blocked the first four hours of every day and used the time to do nothing but write. Early in his real estate career, his top priority was to increase sales. He used his four-hour time block to do nothing but make calls and generate leads for buyers and sellers.

"My motto is: Until my number one priority is done each day, all else is a distraction," he says, adding that four hours is crucial. "If you want to do something at the highest level, it's got to be four hours a day. Time on the task over time – that's how you become a master at what matters most."

2. Work on event time. Keller says most people work on "clock" time, living their life by the clock and by someone else's schedule. They leave work at 5 p.m. because that’s when the workday is over. He works on what he calls "event" time, scheduling the days tasks around the events or goals he wants to accomplish. Everything else -- such as meetings, calls and emails -- wait until he reaches a finishing point. He leaves work when he has accomplished that day's most important priority.

"My most important work comes first and it’s done when it’s done,” he says. “The key to making this work and still getting home in time to have a full and richly rewarding personal life is to block time as early in the day as possible."

3. Block in planning time. In addition to working on his one thing, Keller blocks in time to reflect on where he is and where he wants to be.

"It's the pause before I hit the start button again," he says. "I set aside a day each year for annual planning, an hour each month for monthly planning and an hour each week for weekly planning."

4. Block time off. Keller says time off is crucial, and at the beginning of the year he blocks out long weekends and long vacations. He says time blocking has been the key to living the kind of life he wants.

"If we know where we're going and what we want to accomplish, this gives us amazing clarity on our priority," he says.